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' NTTED STATES PATENT Fricrj.

FRANK XrBLAOK, LINUS P. OLAWSON, AND JAMES A. CONNELLY, OF HAMIL- TON, OHIO, ASSIGNORS TO THE BLACK & CLAXVSON COMPANY, OF SAME PLACE.

EVAPORATOR.

SPECIFICATION forming part of Letters Patent No. 614,607, dated November 22, 1898. Application filed A t 27,1897. Serial No. 649,718. (No model.)

To all whom it may concern.-

Be it known that we, FRANK X. BLACK, LINUs P. OLAwsoN; and JAMESA. CONNELLY, of Hamilton, Butler county, Ohio, have invented certain new and useful Improvements in Machines for Thickening Liquids, (Case F,) of which the following is a specification.

This invention pertains to improvements in machines for thickening liquids by process of transferring heat, as by vaporizing portions of the liquid away by adding heat or by cooling a warm liquid by abstracting heat from it.

Our improvement will be readily understood from the following description, taken in 0011- nection with the accompanying drawings, in which-- Figure 1 is a side elevation, part vertical section, of a machine exemplifying our invention; and Fig. 2, a plan of the same.

In the drawings, 1 indicates a vat adapted' to receive the liquid to be dealt with; 2, the upper surface of the liquid therein; 3, a hollow metallic cylinder mounted in suitable bearings and dipping the lower portion of its periphery into the liquid in the vat; 4:, inletpipe for thermic fluid or liquid into the cylinder; 5, outlet-pipe for the thermic fluid or liquid from the cylinder, the inlet and outlet pipes being illustrated as communicating with the interior of the cylinder through its opposite end journals; 6, gearing connected with one of the necks of the cylinder to exemplify means by which the cylinder may be rotated by power; '7, an inlet for admitting to the vat the liquid to be dealt with; 8, a doctor engaging the periphery of the cylinder at a point over the liquid in the vat at that side of the cylinder approaching the liquid; 9, a second hollow metallic cylinder similar to cylinder 3 and similarly mounted to dip into the liquid in the vat and similarly provided with inlet and outlet pipes and with a doctor, the peripheries of the two cylinders running in contact with each other; 10, adjustable bearings for one or both of the cylinders, exemplifying means by which the peripheries of the two cylinders are brought into proper contact with each other; 11, adjusting devices for securing proper contact between the doctors and their cylinders, and 12 an outlet-pipe for use in emptying the vat.

Assume that the liquid to be dealt with is, as a more example, the so-called tank-water of the packing-house, from which it is desired to get the solid ammoniate. The liquid portion of the matter is to be gotten out by evaporation, leaving a thicker liquid or a solid. In such case in the use of our machine steam or other hot fluid or liquid is to be passed into and through the cylinders 3 and 9. Assume steam to be employed as the thermal fluid in the cylinders. The hot cylinders are set in motion in the direction of the arrows and the liquid to be dealt with is introduced at inlet 7 and maintained in the tank at such level that the lower portions of the cylinders will dip slightly into the liquid. The cylinders as they turn in the liquid in the vat will become wetted or coated thereby. As the coated surfaces of the cylinders travel upwardly out of the tank the heat of the cylinders causes the lighter liquid portions of the matter to evaporate from the coating, the vapor going to the atmosphere and leaving a comparatively dry coating upon the cylinders. This coating is scraped from the cylinders by the doctors, which return it to the vat, where it joins the liquid therein, the cylinders thus continuing to act on the matter in the vat by evaporating from it its lighter liquid portions, the matter in the vat thus getting continually thicker, the operation being continued until the desired degree of consistency or solidity is obtained.

The facility with which the hot cylinders transmit heat to the wetted coating brought up from the vat is dependent largely upon the perfection of contact between that coatin g and the hot surfaces of the cylinders. In dealing with many kinds of liquid it is found that air or gas bubbles form under the coating, thus to that extent insulating the coating from the surface of the cylinder. The

bubble-film thus standing away from the surface of the cylinder and insulated from it would not be properly subjected to the heat of the cylinder; but in our improved machine bubbles thus forming upon the surface of one cylinder as that surface rises from the liquid become smashed down and flattened by the action of the fellow cylinder, the bubble bein g often burst, the result being that the coating becomes pressed down into perfect contact with the surfaces of the cylinders.

In the example of liquid above assumed the thickening of the liquid was elfected by the addition of heat to it, the heat resulting in the evaporation of the lighter liquid portions of the mass. If we assume thatthe liquid to be dealt with was a warm liquid to be thickened by the abstraction of heat from it, then the machine would be used in a similar manner to that above described, but the thermic fluid or liquid supplied within the cylinders would be coldas, for instance, refrigerated air or refrigerated water or brine. In dealing with extremely thin liquids at the beginning of the process the lower surfaces of the cylinders gather the liquid from the vat and tend to carry the gathered liquid upwardly, gravity, however, strongly resisting the upward progress of the liquid, the result being a tendency of the liquid to flow backward and leave the cylinder-surface not properly coated. In our machine the two cylinders dipping into the liquid and having their lower surfaces running toward each other have a tendency to mutually splash each other with the liquid and thus produce a coating application independent of that gathered by the direct bathing of the cylinders--that is to say, one cylinder is of aid in wetting the surface of the other cylinder.

We claim as our invention-- In a machine for thickening liquids, the combination, substantially as set forth, of a vat adapted to receive the liquid to be dealt with, a pair of hollow metallic cylinders mounted for rotation in said vat with their peripheries in contact and with the lower portion of their peripheries dipping into the liquid in the vat, means for varying the te1nperature within the cylinders, and doctors engaging the cylinders to scrape the coating therefrom.

FRANK X. BLACK. LINUS P. OLAWVSON. JAMES A. (JONNELLY.

Witnesses EDWARD I-IELWIG, EDGAR A. BELDEN, SAM D. FrrroN, Jr 

